package lq;

import java.util.Scanner;

public class lq2009 {
    public static void main(String[] args){
        Scanner in = new Scanner(System.in);
        double sum;
        while (in.hasNext()){
            double m = in.nextDouble();
            int n = in.nextInt();
            sum=0;
            for (int i=0;i<n;i++){
                sum+=m;
                m=Math.sqrt(m);
            }
            System.out.printf("%.2f", sum);
            System.out.println();
        }
    }
}
